Her Britannic Majesty, The Queen Elizabeth II of Windsor decided to celebrate the idea of "the devine right of Kingship" for her Jubilee year by hosting a Luncheon for Soverigns of the World at Windsor Castle.

Didnt quite go down to well, mostly because the Monarchies are now subject to their Governments. For example, An invitation was sent to the Spainish Queen who couldnt attend because her bankrupt Government told her not to because they are pissed off at the British Government for protecting Gibralter whilst the rest of spain slides into financial meltdown

The king of The Swaziland in Africa turned up, to be met with hostility because he still lives like Kings of bygone ages whilst his countrymen starve to death in famine. The King of Bahrain also turned up and people were unfriendly to him because his Government tried to quash the democratic rebellions they've suffered recently

Those invited include

Here is a full guest list of foreign royals attending the lunch for sovereign monarchs:

HM The King of Bahrain and HRH Princess Sabeeka bint Ibrahim Al Khalifa,
HM The King of The Belgians and HM The Queen of The Belgians,
HM The Sultan and Yang Di-Pertuan of Brunei and HM Raja Isteri Pengiran Anak Hajah Saleha,
HM King Simeon II of the Bulgarians and HM Queen Margarita of the Bulgarians,
HM Queen Margrethe II of Denmark and HRH The Prince Consort (Denmark),
HM King Constantine of the Hellenes and HM Queen Anne-Marie of the Hellenes, (Greeks)
HM The Emperor of Japan and HM The Empress of Japan,
HM The King of the Hashemite Kingdom of Jordan and HM Queen of the Hashemite Kingdom of Jordan,
HH Sheikh Nasser Mohamed Al-Jaber Al-Sabah of Kuwait,

HM King Letsie III of Lesotho and HM Queen Masenate Mohato Seeiso of Lesotho,
HSH Prince Hans-Adam II of Liechtenstein,
HRH The Grand Duke of Luxembourg and HRH The Grand Duchess of Luxembourg,
HM Seri Paduka Baginda Yang di-Pertuan Agong of Malaysia and HM Seri Paduka Baginda, Raja Permaisuri of Malaysia,
HSH The Prince of Monaco and HSH The Princess of Monaco
HRH Princess Lalla Meryem of Morocco,
HM The Queen of the Netherlands,
HM The King of Norway and HM The Queen of Norway,
HH The Emir of The State of Qatar and HH Sheika Mozah bint Nasser Al-Missned,
HM King Michael I of Romania and HM Queen Anne of Romania,
HRH Prince Mohammed Bin Nawaf Bin Abdulaziz Al Saud of Saudi Arabia,
HM King Mswati III of Swaziland and Inkhosikati LaMbikiza,
HM The King of Sweden and HM The Queen of Sweden,
HRH The Crown Prince of Thailand and HRH Princess Srirasm of Thailand,
HM The King of Tonga and HM The Queen of Tonga,
HH The Crown Prince of Abu Dhabi,
HRH The Crown Prince of Yugoslavia and HRH The Crown Princess of Yugoslavia. (Whose Country no longer even exists!)

The Pope (Who was entitled as an Ellected Monarch of The Vatican city State, however, he visited not so long ago, is quite old, and his travels might have garnered too much attention and danger as hosts.

Oman was not invited probably because he took power via a coup and runs his ship like a captainBhutan was not invited to attend possibly because his countries geography would make travel difficult and he'd almost certainly be reluctant to leaveCambodia Was not invited to attend pol pot noodle anyone

Aparently Monaco has the longest reigning Monarch in Europe (although the invited guest was his successor) The Thai Crown is worn by the worlds longest reigning Monarch...he's still very much alive...and Denmark earns the reward of longest continuous monarchy, whilst we have longest monarchy (the problem is that the first 500 years arguably their were three crowns covering different parts of England, and of course the embarissment of the Protectorate after the Civil war...there are arguments to say as the Kings son was never killed the line remained unbroken and he was king, but he rulled in exhile...depends how you view it )